CVE-2021-20591 Explained : Impact and Mitigation

A vulnerability has been discovered in Mitsubishi Electric MELSEC iQ-R series CPU modules that could allow a remote attacker to trigger a denial of service condition by not closing a connection properly.

Understanding CVE-2021-20591

This section provides detailed insights into the CVE-2021-20591 vulnerability.

What is CVE-2021-20591?

CVE-2021-20591 is an Uncontrolled Resource Consumption vulnerability found in Mitsubishi Electric MELSEC iQ-R series CPU modules. It allows an attacker to disrupt legitimate client connections to the MELSOFT transmission port.

The Impact of CVE-2021-20591

Exploitation of this vulnerability could result in a denial of service (DoS) condition, affecting the availability of services.

Technical Details of CVE-2021-20591

Explore the technical aspects of the CVE-2021-20591 vulnerability below.

Vulnerability Description

The vulnerability arises from the CPU modules' inability to properly close connections, allowing attackers to consume resources.

Affected Systems and Versions

MELSEC iQ-R series CPU modules, including versions R00/01/02CPU, R04/08/16/32/120(EN)CPU, R08/16/32/120SFCPU, R08/16/32/120PCPU, and R08/16/32/120PSFCPU, are impacted.

Exploitation Mechanism

Remote unauthenticated attackers can exploit this vulnerability by failing to close connections correctly, leading to a DoS condition.

Mitigation and Prevention

Learn how to mitigate and prevent the exploitation of CVE-2021-20591 below.

Immediate Steps to Take

Organizations should consider applying security patches promptly and implementing network segmentation to minimize the attack surface.

Long-Term Security Practices

Regularly update systems and monitor network traffic for any suspicious activities to enhance overall cybersecurity.

Patching and Updates

Stay informed about security updates from Mitsubishi Electric and apply patches as soon as they are released.